Hydra - Skyline

The largest known entity is the Mother Ships which comes in all shapes and size but is usually several hundred meters long and able to travel interstellar distances, transporting the smaller specimens of the species. They seem to be moving in pack from worlds to worlds. There seems to also be smaller anthropomorph aliens which stays inside the mothersip and most likely others which have not been witnessed yet.

Hydras

from the movie
Skyline